If you put "VerifyReverseMapping no" in your sshd configuration file,
you won't see these messages.  Having VerifyReverseMapping turned on
is of dubious value anyway.
   From http://www.webservertalk.com/message446383.html

As for the rest of it - sounds like faxserver is basically having DNS
problems.  

I assume that 192.168.1.18 and .19 are fidelo and admin, and are running
bind9 correctly (ie, other machines can look up DNS stuff) ?

Is this network connected to the net?  Or is it isolated?

These machines are all linux boxes right?

Could it be a missing dot in the bind config files?  Or spaces instead of
tabs?  Some of those are hideously hard to trace.

Also - check in ifconfig that the lo interface is up.  I've seen excessive
weirdness when some smartarse has done a  ifconfig lo down

Do you use NFS or NIS ?


-----Original Message-----
From: David Kirk [mailto:[EMAIL PROTECTED] 
Sent: Monday, 1 November 2004 2:18 p.m.
To: [EMAIL PROTECTED]
Subject: Reverse DNS Lookups from SuSE 9.1

When I remotely access the server with ssh, I type in my user name and then
have to wait about 20 seconds for the password prompt.  This is what
/var/log/messages says about it:

   Nov  1 12:53:50 faxserver sshd[17147]: reverse mapping checking
getaddrinfo for
   david.chchcasino.local failed - POSSIBLE BREAKIN ATTEMPT!

I run yast and select Network Services -> DNS and Host Name.  The host name
and domain name are faxserver.chchcasino.local.  Name Server 1 and 2 show
the IP addresses of our DNS servers and Domain Search 1 shows
chchcasino.local.  And just to be sure:

   [EMAIL PROTECTED]:~> cat /etc/resolv.conf
   nameserver 192.168.1.18
   nameserver 192.168.1.19
   search chchcasino.local

So, I do a lookup on david.chchcasino.local:

   [EMAIL PROTECTED]:~> dig david.chchcasino.local

   ; <<>> DiG 9.2.3 <<>> david.chchcasino.local
   ;; global options:  printcmd
   ;; Got answer:
   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21462
   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
 
   ;; QUESTION SECTION:
   ;david.chchcasino.local.                IN      A

   ;; ANSWER SECTION:
   david.chchcasino.local. 86400   IN      A       192.168.1.81

   ;; AUTHORITY SECTION:
   chchcasino.local.       86400   IN      NS      fidelio.chchcasino.local.
   chchcasino.local.       86400   IN      NS      admin.chchcasino.local.

   ;; ADDITIONAL SECTION:
   fidelio.chchcasino.local. 86400 IN      A       192.168.1.18
   admin.chchcasino.local. 86400   IN      A       192.168.1.19

   ;; Query time: 3 msec
   ;; SERVER: 192.168.1.18#53(192.168.1.18)
   ;; WHEN: Mon Nov  1 13:15:20 2004
   ;; MSG SIZE  rcvd: 146

and a reverse lookup on my IP address:

   [EMAIL PROTECTED]:~> dig -x 192.168.1.81

   ; <<>> DiG 9.2.3 <<>> -x 192.168.1.81
   ;; global options:  printcmd
   ;; Got answer:
   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62387
   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
   
   ;; QUESTION SECTION:
   ;81.1.168.192.in-addr.arpa.     IN      PTR
   
   ;; ANSWER SECTION:
   81.1.168.192.in-addr.arpa. 86400 IN     PTR     david.chchcasino.local.
   
   ;; AUTHORITY SECTION:
   168.192.IN-ADDR.ARPA.   86400   IN      NS      fidelio.chchcasino.local.
   168.192.IN-ADDR.ARPA.   86400   IN      NS      admin.chchcasino.local.
   
   ;; ADDITIONAL SECTION:
   fidelio.chchcasino.local. 86400 IN      A       192.168.1.18
   admin.chchcasino.local. 86400   IN      A       192.168.1.19
   
   ;; Query time: 3 msec
   ;; SERVER: 192.168.1.18#53(192.168.1.18)
   ;; WHEN: Mon Nov  1 13:16:03 2004
   ;; MSG SIZE  rcvd: 173

That all looks good to me.

But it gets worse.  Hylafax also wants to do reverse lookups.  If I use WHFC
(the Windows Hylafax Client), or telnet to faxserver on port 4559, I get the
20 second delays and the following error message in
/var/log/messages:

   Nov  1 12:56:11 faxserver HylaFAX[17172]: <--- 130 Warning, no inverse
address
   mapping for client host name "david.chchcasino.local".

And worse still, postfix can't find our internal mail server.  Here is what
mailq says:

   B76E7A441       701 Fri Oct 29 16:23:54  [EMAIL PROTECTED]
                          ([mail.chchcasino.local]: Name or service not
known)
                                         [EMAIL PROTECTED]

But I say it is there:

   [EMAIL PROTECTED]:~> dig -t mx chchcasino.local
   
   ; <<>> DiG 9.2.3 <<>> -t mx chchcasino.local
   ;; global options:  printcmd
   ;; Got answer:
   ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10386
   ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3
   
   ;; QUESTION SECTION:
   ;chchcasino.local.              IN      MX
   
   ;; ANSWER SECTION:
   chchcasino.local.       86400   IN      MX      10 mail.chchcasino.local.
   
   ;; AUTHORITY SECTION:
   chchcasino.local.       86400   IN      NS      fidelio.chchcasino.local.
   chchcasino.local.       86400   IN      NS      admin.chchcasino.local.
   
   ;; ADDITIONAL SECTION:
   mail.chchcasino.local.  86400   IN      A       192.168.1.13
   fidelio.chchcasino.local. 86400 IN      A       192.168.1.18
   admin.chchcasino.local. 86400   IN      A       192.168.1.19
   
   ;; Query time: 4 msec
   ;; SERVER: 192.168.1.18#53(192.168.1.18)
   ;; WHEN: Mon Nov  1 13:23:07 2004
   ;; MSG SIZE  rcvd: 145
   
So, after all that, does anyone know why dig can see all that stuff but
sshd, hylafax and postfix can't?

If I add myself in to /etc/hosts, sshd and hylafx all work at normal speeds.

While writing this e-mail, I also tried to ping some of these hosts. 
It turns out that I can ping the IP addresses, but not the host names:

   [EMAIL PROTECTED]:~> ping -c 1 david.chchcasino.local
   ping: unknown host david.chchcasino.local

   [EMAIL PROTECTED]:~> ping -c 1 192.168.1.81
   PING 192.168.1.81 (192.168.1.81) 56(84) bytes of data.
   64 bytes from 192.168.1.81: icmp_seq=1 ttl=128 time=0.354 ms
   
   --- 192.168.1.81 ping statistics ---
   1 packets transmitted, 1 received, 0% packet loss, time 0ms
   rtt min/avg/max/mdev = 0.354/0.354/0.354/0.000 ms

Very strange.  dig (and host and nslookup) can do DNS lookups, but nothing
else can.

The same thing happens when I telnet to the mail server on port 25.  I can
telnet 192.168.1.13 25 but not mail.chchcasino.local 25.


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